Many hand held portable electrical and electronic devices, such as point-of-sale barcode readers or scanners, have one or more button or trigger actuators for activating one or more functions of the device. For example, in a hand held point-of-sale barcode scanner, a trigger actuator is provided for activating an electrical switch associated with a laser source such as a visible laser diode (VLD) to generate the laser beam that scans barcodes. These trigger actuators or actuation mechanisms may come in a variety of mechanical configurations and generally have a trigger or button that the user presses to activate the laser scan function. Although it is possible that the trigger be an integral part of the electrical switch that electrically activates the laser beam scanner, more often the button may be a separate structure that is directly or indirectly linked to the switch inside the hand held device. Often, the trigger is shaped to aesthetically blend in with the shape and appearance of the hand held device. In addition, the size of the trigger may be substantially enlarged in comparison to the actual electrical switch to provide a more robust and appropriately sized tactile trigger surface to accommodate a user's finger. The trigger may therefore be merely a mechanical linkage that transfers the external force exerted on the trigger by a user's finger directly to the switch located inside the hand held electrical or electronic device.
Conventional button or trigger mechanisms for hand held barcode scanners are often of a hinged design with the trigger being coupled to the scanner housing about a single pivot point. Hinged trigger mechanisms for scanners are traditionally formed of molded hard plastic. To establish the pivot point, pivotable hinged triggers often require special intricate molded and/or machined features to be incorporated into the scanner housing and corresponding portions of the trigger mechanism. Such conventional hinged trigger designs, however, have drawbacks. First, the trigger design may become mechanically complex sometimes requiring extra components such as metal pins to form the hinged pivot in addition to requiring intricate molded and/or machines features. These factors translate into higher manufacturing costs for the barcode scanners or readers. Second, the intricate trigger hinges sometimes are not sufficiently robust enough to withstand heavy commercial and industrial usage without trigger malfunctions or breakage. Third, the single hinged pivot point often lacks a smooth tactile feel when the user depresses the trigger because the amount of finger pressure required to fully actuate the trigger and corresponding electrical switch associated with the trigger varies as the distance from the trigger pivot point increases. Therefore, the finger pressure may vary depending on where on the trigger face or surface the user presses. Traditional hinged trigger designs also typically lack a tactilely “soft” feel because trigger travel limit stops are sometimes formed by only hard surfaces on the trigger coming into abutting contact with corresponding hard surfaces on the scanner housing and/or trigger receptacle.
An improved button or trigger mechanism is desired.